A multicenter, ongoing study of early-diagnosed cases of systemic sclerosis and comparison patients with systemic lupus erythematosus, polymyositis/dermatomyositis, and Raynaud's phenomenon was conducted in order to develop classification criteria for systemic sclerosis. Preliminary criteria are proposed namely, the finding of either the sole major criterion, i.e., proximal scleroderma, or two or more of the minor criteria, i.e., 1) sclerodactyly, 2) digital pitting scars of fingertips or loss of substance of the distal finger pad, and 3) bilateral basilar pulmonary fibrosis. When applied to the case and comparison patients included in this study, these proposed criteria had a 97% sensitivity for definite systemic sclerosis and 98% specificity.